Complete question :
A jeweler has five rings, each weighing 18 g, made of an alloy of 10% silver and 90% gold. She decides to melt down the rings and add enough silver to reduce the gold content to 75%. How much silver should she add?
Answer:
Kindly check explanation
Explanation:
Given the following :
Weight of each alloy = 18g
Initial % of Silver = 10% = 0.1
Initial % of Gold = 90% = 0.9
New % of gold = 75% = 0.75
Hence, new % of silver will be (1 - 0.75) = 0.25
Let the amount of silver to be added = s
Hence,
Initial gold content = final gold content + added silver
18 * 0.9 = 0.75(18 + s)
16.2 = 13.5 + 0.75s
16. 2 = 13.5 + 0.75s
16.2 - 13.5 = 0.75s
2.7 = 0.75s
s = 2.7 / 0.75
s = 3.6
S = 3.6
Hence the amount of silver needed per ring in other to reduce the gold content = 3.6g
Total for the 5 rings = (3.6 * 5) = 18g
HELP! Ethanol has a density of 0.8 g/cm3. a. What is the mass of 225 cm3 of ethanol? b. What is the volume of 75.0 g of ethanol?
Answer:
The correct answers are:
a) 180 g
b) 93.7 cm³
Explanation:
The density of a substance is the mass of the substance per unit of volume. So, it is calculated as follows:
density= mass/volume
From the data provided in the problem:
density = 0.8 g/cm³
a) Given: volume= 225 cm³
mass= density x volume = 0.8 g/cm³ x 225 cm³ = 180 g
b) Given: mass= 75.0 g
volume = mass/density = 75.0 g/(0.8 g/cm³)= 93.75 cm³≅ 93.7 cm³
Taking into account the definition of density:
the mass of 225 cm³ of ethanol is 180 g.the volume of 75.0 g of ethanol is 93.75 cm³.Definition of densityDensity is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.
In other words, density is a quantity that allows us to measure the amount of mass in a certain volume of a substance. Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
[tex]density=\frac{mass}{volume} [/tex]
From this expression it can be deduced that density is inversely proportional to volume: the smaller the volume occupied by a given mass, the higher the density.
Mass of 225 cm³ of ethanolIn this case, you know that:
Density= 0.8 [tex]\frac{g}{cm^{3} } [/tex]Volume= 225 cm³Replacing in the definition of density:
[tex]0.8 \frac{g}{cm^{3} } =\frac{mass}{225 cm^{3} } [/tex]
Solving:
mass= 0.8 [tex]\frac{g}{cm^{3} } [/tex] ×225 cm³
mass= 180 g
In summary, the mass of 225 cm³ of ethanol is 180 g.
Volume of 75.0 g of ethanolIn this case, you know that:
Density= 0.8 [tex]\frac{g}{cm^{3} } [/tex]mass= 75 gReplacing in the definition of density:
[tex]0.8 \frac{g}{cm^{3} } =\frac{75 g}{volume} [/tex]
Solving:
0.8 [tex]\frac{g}{cm^{3} } [/tex] ×volume= 75 g
volume= 75 g÷ 0.8 [tex]\frac{g}{cm^{3} } [/tex]
volume= 93.75 cm³
Finally, the volume of 75.0 g of ethanol is 93.75 cm³.
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. Identify each of the following statements as being most similar to a hypothesis, a law, or a theory. Explain your reasoning.
(a) Falling barometric pressure precedes the onset of bad weather.
(b) All life on earth has evolved from a common, primitive organism through the process of natural selection.
(c) My truck’s gas mileage has dropped significantly, probably because it’s due for a tune-up.
(a). law (states a consistently observed phenomenon, can be used for prediction); (b). theory (a widely accepted explanation of the behavior of matter); (c). hypothesis (a tentative explanation, can be investigated by experimentation)
What is law, hypothesis and theory ?A law is defined as the verified statement that will always be true for the specified conditions.A hypothesis is defined as the generalized statement that is not based upon any verification or test. Basically, a hypothesis is a guess that we have to verify through test or experimentation.A theory is defined as an in-depth information about a verified fact or observed phenomenon.Learn more about law here ;
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Comprised of protons, neutrons, and electrons.
Answer:
The atom
Explanation:
A mixture is made by combining 1.17 lb of salt and 3.54lb of water.What is the percentage of salt (by mass) in this mixture?
Answer:
The percentage of salt in the mixture 24.84%
Explanation:
In this problem we are required to solve for the percentage of salt in the mixture of salt and water
Step one :
We can proceed by first solving for the total mass of the mixture
Which is given as
mass of mixture =mass of salt +mass of water
Mass of mixture = 1.17+3.54
Mass of mixture = 4.71 lb
Step two :
Now let us calculate the percentage of salt present in the mixture which is
=(mass of salt/mass of mixture) *100
=(1.17/4.71)*100
=0.248*100
=24.84%
What is the answer: 20°C to °F?
Answer:
68 degrees fahrenheit
Explanation:
b. 239/94 Pu 4/2 He +
Answer:
im thinking its 362x
Explanation:
28. Analyzing Results A pure white, solid material that
looks like table salt releases gas when heated
under certain conditions. There is no change in
the
appearance of the solid, but the reactivity of
the material changes.
a. Did a chemical or physical change occur? How do
you know?
b. Was the original material an element or
a compound?
Answer:
a :Chemical b : compound
Explanation:
a : it had to be a chemical change because it says "There is no change in
the appearance of the solid, but the reactivity of the material changes.
b : well it would be a compound because it would have to be to make a reaction
There is no change is the appearance of the solid, but the reactivity of the material changes. In case of question a :Chemical changes occur and in case of question b : The original material is compound.
What are the properties of a compound ?A compound is defined as the material that is composed up of two or more elements by chemically combined with each other in a fixed proportion by their mass.
Examples are Water, Sodium Chloride, Ammonium Chloride etc; They have a fixed melting and boiling points, a compound can be changed in chemical reaction and hence the components are mixed in a fixed proportion.
Two primary types of compounds are covalent and ionic compounds as it is bonded by covalent and ionic bond, the formation of covalent bond occur between two nonmetals, like water or methane. These molecules are neutral and weak.
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What is the TLV for sodium hydroxide? Will mark brainliest!
Answer:
you could've googled it but here.
Explanation:
The former OSHA limit for sodium hydroxide (also known as caustic soda or Iye) was 2 mg/m3 as an 8-hour TWA. OSHA proposed a 2-mg/m3 ceiling limit for sodium hydroxide, based on the ACGIH- and NIOSH-recommended limits.
what method is suitable to determine whether barium is more reactive than calcium
Answer:
by looking at the number of electrons in the outermost shell of an atom determines its reactivity (the number on top of the column)
Explanation:
calcium and barium are both in column 2, since barium is located further in the column, it's more reactive
plus barium also have a larger mass than calcium
how can the existence of atoms help to explain the law of define proportions .
Answer:
Atoms of same element can combine in more than one ratio to form two or more compounds. Atoms are the smallest unit of matter that can take part in a chemical reaction. The law of definite proportions states that a chemical compound always contains exactly the same proportion of elements by mass.
Explanation:
Hope this helps :)
Which of the following statements describe P-waves? Select the two correct answers.
A. They are the first waves detected after an earthquake.
B. They are the most destructive earthquake waves.
C. They alternately compress and pull apart the partides in matter.
D. They can only travel through the solid rock inside Earth.
Answer: C- they alternately compress and pull apart the particles in matter
A -they ate the first waves detected after and earthquake
Explanation:
Answer:
A&C
Explanation:
APEEXX
13. A sample of copper has a volume of 14.75 cm3. The density of copper is 8.96 g/cm3. What is the mass of this sample?
Answer:
The answer is
132.16 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume of copper = 14.75 cm³
Density = 8.96 g/cm³
The mass is
mass = 8.96 × 14.75
We have the final answer as
132.16 gHope this helps you
Jim went for a 3.75 hour run. How many minutes did he run?
Determine which physical properties are being described.
a. Copper wire is used to transfer electricity.
b. There are 19.3 grams of gold in one cubic centimeter.
c. Iron turns to liquid at 1,534.85°C. Silver is very easy to bend.
d. Fluorite is a green crystal.
Answer:
Explanation:
a. Copper wire is used to transfer electricity.
Physical property : Electrical conductivity .
b. There are 19.3 grams of gold in one cubic centimeter.
Physical property : Density
c. Iron turns to liquid at 1,534.85°C.
Physical Property : Melting point
d. Fluorite is a green crystal.
Physical property : Colour .
Answer:
Explanation:
A: Conductivity
B: Density
C: Melting point
D: Hardness
E: Color
What is the density of a 700 kg object with a volume of 649 m3? (Density: D = D = m over v.) 0.927 kg/m3 .4543 kg/m3 1.079 kg/m3 4.543 kg/m3
Answer:
.4543
Explanation:
Answer:
0.927 i just did it on edg. 2020
Explanation:
Express the following numbers in scientific notation:
1. 0.00125
2.
2,000,000,000
3. 796,000
Express the following numbers in scientific notation
An acetaminophen suspension for infants contains 80 mg/0.80 mL suspension. The recommended dose is 15 mg/ kg body weight. How many mL of th is suspension should be given to an in fant weighing 14 lb? (Assume two significant figures.)
Answer:
the answer is 35mg and 58ml
An Olympic swimming pool is 50 meters long. You swim from one end to the other four times.How many meters do you swim?
Answer:
200 meters
Explanation:
if u swim for each end 4 times, and its 50 meters long, 50 x 4 = 200 meters
What is wind?
(1 Point)
air that moves upward
air that moves downward
air that moves from high pressure to low pressure
air that moves from low pressure to high pressure
Answer:
air that moves from high pressure to low pressure
5(3x)-7y2=?,when x=3 and y =2
Answer:
17
Explanation:
We are given the equation:
[tex]5(3x)- 7y^2[/tex]
and asked to solve when x=3 and y=2. Therefore, we must plug 3 in for x and 2 in for y.
[tex]5(3(3))-7(2)^2[/tex]
Solve according to PEMDAS: Parentheses, Exponents, Multiplication, Addition and Subtraction.
Solve the exponent first.
⇒ (2)²= 2*2=4
[tex]5(3(3))-7(4)[/tex]
Multiply 3 and 3.
⇒3*3=9
[tex]5(9)-7(4)[/tex]
Multiply 5 and 9.
⇒5*9=45
[tex]45-7(4)[/tex]
Multiply 7 and 4.
⇒ 7*4=28
[tex]45-28[/tex]
Subtract 28 from 45.
[tex]17[/tex]
5(3x)-7y² when evaluated for x=3 and y=2 is 17
How do we know atoms exist if we can’t see them?
Answer:
Explanation:
Because it's in your hands and there so small that a scientist would need a full scan from the body
What is the difference between a theory and a law in science
What would it take for Americans today to favor a greater reliance on nuclear power as a source of electricity
Answer:
yes
Explanation:
mmmm
The following properties are either physical or chemical. Which one is different from the rest based on those two categories?
Answer:
Boiling point: physical
Density: physical
Ductility: physical
Heat of combustion: chemical
Explanation:
Chemical properties can only be analyzed by putting the substance through a chemical reaction, such as combustion.
Physical properties can be analyzed without altering the substance chemically. With that in mind:
Boiling point is the physical property, density is the physical property, ductility is also a physical property but combustion of heat is a chemical property.
What is physical and chemical property?A physical property is the characteristic of a substance or compound that is observed without any change in the identity of the particular substance.
The physical properties of a substance is its colour, hardness, density, and melting as well as boiling points.
A physical property is a characteristic of matter that involves in physical change and physical changes are reversible and there is no production of any new substance.
The chemical change is the property of a substance due to which new substances are formed and it is non reversible change.
The chemical properties are flammability, toxicity, heat of combustion, coordination number, enthalpy of formation, and oxidation states.
Therefore, Boiling point is the physical property, density is the physical property, ductility is also a physical property but combustion of heat is a chemical property.
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The following properties are either physical or chemical. Which one is different from the rest based on those two category? A.) Density B.) Appearance C.) Color D.) Reactivity
Answer:
A.)physical B.)physical C.)physical D.)chemical
explain why the following statement is false: “if a theory is accepted for a long time, it eventually becomes a law.” include specific details about both theories and laws in your explanation.
Explanation:
hope this will help you
The weight of a cup with water is 2.58 kg the weight of the empty cup is 1.5 kg considering significant figures what is weight of the water
Answer:
The correct answer is 1.1 kg
Explanation:
From the data provided:
Weight (cup + water)= 2.58 kg
Weght (cup) = 1.50 kg
Thus, we simply calculate the difference between the full cup and the empty cup to obtain the net weight of water:
Weight (water) = Weight (cup + water) - Weght (cup)
= 2.58 kg - 1.50 kg
= 1.08 kg ≅ 1.1 kg
Answer: chemistry f sucks
Explanation:
bc it's f stupid
Which describes density? amount of volume for a given object ability of an object to take up space amount of mass in a given volume ability of an object to float in water
amount of mass in a given volume
Amount of mass in a given volume perfect describes the meaning of density. Hence option C is correct.
What is density?Density is the term used to describe the relation between the mass of the body and their volume. Density is a property that can be used to identify substances. Each substance has a unique density.
Example: wood ball density is less as compared to metal ball because wood ball is less than metal ball.
It describes how much matter is packed into a certain volume.
D = M/V
M =Mass (gram); V = Volume (ml or cm3); D = Density (gram/cm3)
Amount of mass in a given volume perfect describes the meaning of density. Hence option C is correct.
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A silver coin with a mass of 14.1g has a density of 10.5 grams
What is the volume of the coin in cm??
cm
Answer:
1.34 cubic centimeter
Explanation:
v = m/d
Can someone help me with this i don't understand it.
Answer:
The subscript next to the letter "C" will always tell you the number of carbon atoms.